Abstract: A tilt servo circuit for controlling an optical axis of an optical pickup perpendicularly to the surface of an optical disc such as a Laser Vision Disc or a Compact Disc playbed back by an optical disc playback device comprises a RF level detection circuit for detecting level of an RF reproduced signal from an optical pickup, a tilt changing circuit for changing a tilt angle of the optical pickup, and a tilt servo control circuit for controlling the tilt changing circuit so as to bring the RF level to maximum or substantially maximum. The level of the RF reproduced signal varies with inclination of laser beam with respect to the perpendicular direction to the disc surface, namely the RF level is at the maximum when the inclination is zero and it decreases as the inclination increases. By detecting the RF level and controlling the tilt changing circuit in a manner to bring the RF level to the maximum, the inclination of the optical axis of the laser beam can be corrected.

Abstract: A disc automatically setting device of a disc player, including: a tray assembly supported on a disc player body to be horizontally movable between an open position where an information carrier disc is placed on a disc support portion of the tray assembly and a shut position where the information carrier disc is placed on a turntable and rotated for playback by rotating the turntable; and a clamping assembly movable between an upper limit position and a lower limit position to clamp the information carrier disc against the turntable when the tray assembly is in the shut position. The disc automatically setting device is provided with a cam mechanism for actuating both of the tray assembly and the clamping assembly and with a drive mechanism, mounted on the disc player body, for driving the cam mechanism to actuate the tray assembly and the clamping assembly.

Abstract: A tape speed switching device in a cassette tape recorder capable of selecting a tape transport speed for recording and playback among a plurality of different speeds, comprises a cassette ejecting mechanism and a tape speed switching mechanism which are mechanically coupled to each other. The tape speed switching mechanism is operated in association with the operation of the cassette ejecting mechanism, so that the tape speed is set to a predetermined one every time when the ejecting mechanism is operated.

Abstract: In an operating mechanism of a tape recorder wherein play, fast forward running and rewinding modes are switched by a pair of solenoids through an operating plate, the operating plate is rotated about a center of rotation when either one of the solenoids is energized but moved linearly when both solenoids are energized. There are also provided a head mechanism for moving a recording and reproducing head to a play position during play mode but separating the head from the play position during another modes, a spring for urging the head away from the play position, and a brake mechanism connected to the plunger of one solenoid to apply a braking force to the take-up and supply reel posts when both solenoids are not energized and to separate the brake mechanism from the take-up and supply reel posts when either one of the solenoid is energized.